function str_ireplace(search, replace, subject) {
  //  discuss at: http://phpjs.org/functions/str_ireplace/
  // original by: Martijn Wieringa
  //    input by: penutbutterjelly
  //    input by: Brett Zamir (http://brett-zamir.me)
  // improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // improved by: Jack
  // bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // bugfixed by: Onno Marsman
  // bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // bugfixed by: Philipp Lenssen
  //   example 1: str_ireplace('l', 'l', 'HeLLo');
  //   returns 1: 'Hello'
  //   example 2: str_ireplace('$', 'foo', '$bar');
  //   returns 2: 'foobar'

  var i, k = '';
  var searchl = 0;
  var reg;

  var escapeRegex = function (s) {
    return s.replace(/([\\\^\$*+\[\]?{}.=!:(|)])/g, '\\$1');
  };

  search += '';
  searchl = search.length;
  if (Object.prototype.toString.call(replace) !== '[object Array]') {
    replace = [replace];
    if (Object.prototype.toString.call(search) === '[object Array]') {
      // If search is an array and replace is a string,
      // then this replacement string is used for every value of search
      while (searchl > replace.length) {
        replace[replace.length] = replace[0];
      }
    }
  }

  if (Object.prototype.toString.call(search) !== '[object Array]') {
    search = [search];
  }
  while (search.length > replace.length) {
    // If replace has fewer values than search,
    // then an empty string is used for the rest of replacement values
    replace[replace.length] = '';
  }

  if (Object.prototype.toString.call(subject) === '[object Array]') {
    // If subject is an array, then the search and replace is performed
    // with every entry of subject , and the return value is an array as well.
    for (k in subject) {
      if (subject.hasOwnProperty(k)) {
        subject[k] = str_ireplace(search, replace, subject[k]);
      }
    }
    return subject;
  }

  searchl = search.length;
  for (i = 0; i < searchl; i++) {
    reg = new RegExp(escapeRegex(search[i]), 'gi');
    subject = subject.replace(reg, replace[i]);
  }

  return subject;
}